CN103245301B - Three-dimensional measuring apparatus - Google Patents
Three-dimensional measuring apparatus Download PDFInfo
- Publication number
- CN103245301B CN103245301B CN201210275511.5A CN201210275511A CN103245301B CN 103245301 B CN103245301 B CN 103245301B CN 201210275511 A CN201210275511 A CN 201210275511A CN 103245301 B CN103245301 B CN 103245301B
- Authority
- CN
- China
- Prior art keywords
- band electrode
- light
- liquid crystal
- group
- light pattern
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Length Measuring Devices By Optical Means (AREA)
- Liquid Crystal (AREA)
Abstract
The three-dimensional measuring apparatus that effectively can improve measuring accuracy is provided.Base board checking device comprises: irradiation unit printed base plate being irradiated to the light pattern of striated; To the camera that light pattern is taken; And the control device of three-dimensional measurement is carried out based on the view data of taking.Irradiation unit comprises radiative light source and this light is converted to the liquid crystal grating (4b) of light pattern of striated.Liquid crystal grating (4b) is formed with liquid crystal layer between a pair glass substrate (31,32), and comprises the public electrode (33) be configured on one of them glass substrate (31) and the multiple band electrodes (34) be disposed side by side on another glass substrate (32).And, band electrode (34) is divided into the group that 6 is 1 group, the band electrode (34a) etc. of each group is connected in parallel separately from each other, described band electrode (34a) group etc. be connected in parallel is connected with same on-off element (36a ~ 36f) respectively, and is controlled respectively by this on-off element (36a ~ 36f).
Description
Technical field
The present invention relates to three-dimensional measuring apparatus.
Background technology
In general, when during mounting electronic parts, being first disposed in printing soldering paste on the predetermined electrode pattern on printed base plate on printed base plate.Then, electronic unit is temporarily fixed on printed base plate by the viscosity based on this solder cream.Afterwards, described printed base plate is placed into reflow ovens, welds through predetermined reflow process.So far, the stage before putting into reflow ovens needs the printing state checking solder cream, sometimes uses three-dimensional measuring apparatus when carrying out this inspection.
In recent years, propose the three-dimensional measuring apparatus that the various what is called making to use up is contactless, such as, propose the technology relevant with using the three-dimensional measuring apparatus of phase-shifting method.
Utilize in the three-dimensional measuring apparatus of phase-shifting method above-mentioned, irradiate light pattern by illumination unit to measured object (in the case for printed base plate), illumination unit is made up of the combination of grating of the light source launching predetermined light and the light pattern that the light penetrated from this light source converted to the light distribution with sinusoidal wave shape (striated).Afterwards, the image unit using the top immediately preceding the point on substrate to configure observes the point on described substrate.Image unit can use the CCD camera etc. comprising lens and picture pick-up device etc.
In addition, the above-mentioned grating for the formation of light pattern can enumerate the liquid crystal grating etc. be such as made up of liquid crystal cell.
Usually, liquid crystal grating is formed with liquid crystal layer between a pair transparency carrier, and be included in the public electrode that one of them transparency carrier configures, and be disposed side by side on multiple band electrodes on another transparency carrier and relative with public electrode, this liquid crystal grating carries out switch control rule by driving circuit to the on-off element (thin film transistor (TFT) etc.) be connected with each band electrode respectively, and the grating pattern ((a) of reference Figure 12) of the striated be made up of high " the bright portion " of light transmission rate and low " dark portion " of light transmission rate is formed by the voltage controlling to be applied to each band electrode.Further, the light be irradiated on measured object via this liquid crystal grating becomes the light pattern ((b) with reference to Figure 12) with sinuous light distribution by the fuzzy grade caused due to diffraction.
Under the above constitution, intensity (brightness) I of the light of each pixel on the image taken by camera head can be provided by following formula (1).
Wherein, e: direct current light noise (offset component), f: sinusoidal wave contrast (contrast) (reflectivity),
the phasing degree of the sine wave in this pixel.
Here, controlling by carrying out switching to above-mentioned grating, is such as four-stage by the phase change of light pattern
obtain and there is intensity distributions I0 corresponding with it, the image of I1, I2, I3, and try to achieve phasing degree based on following formula (2)
Then, this phasing degree is used
principle based on triangulation calculates the height (Z) of the preset coordinates position (X, Y) on printed base plate (solder cream).Measure the three-dimensional shape of measuring object thus.
With preset coordinates position (X, Y) relevant phasing degree changes according to its height, such as at this coordinate position (X, Y) when the height (Z) at place is " O ", be irradiated to this coordinate position (X, the phasing degree of pattern light Y) is " 0 ° ", and phasing degree becomes " 10 ° " etc. when having predetermined altitude.
Here, simple declaration uses the height operational method of the principle of triangulation.Such as shown in Figure 13,14, when to make vertical and parallel with the Y direction mode of the striped of light pattern and X-direction irradiate, if the vertical curve of lighting device 90 and angle formed by irradiation light when irradiating from lighting device 90 to the measuring object point h solder cream H are set to ε, then this angle ε represents by the following formula (3) of the X-coordinate (Xj) based on the some j on reference plane.
ε＝f(Xj)…(3)
Further, height Z is derived by following formula (4).
Z＝Lh-Lpc/tanε+Xh/tanε…(4)
Wherein, Lh: lighting device 90 relative to the height of reference field, Lpc: camera 91 and lighting device 90 distance in the X-axis direction, Xh: the X-coordinate of measuring object point h.
But, in above-mentioned liquid crystal grating, because the characteristic (offset and gain etc.) of each transistor of being connected with each band electrode exists deviation, also there is deviation in the voltage being applied to each band electrode above-mentioned, therefore identical even " bright portion " and " dark portion ", also there is deviation ((a) with reference to Figure 15) in the light transmission rate (luminance level) of each row corresponding with each band electrode.Consequently, the light pattern be irradiated on measured object does not have sinuous desirable light distribution ((b) with reference to Figure 15) yet, and three-dimensional measuring result may produce error.In addition, in fig .15 exemplified with the situation being made up of the one-period of light pattern 6 row (6 strip electrode).
Therefore, in the past, grasped the deviation (PHASE DISTRIBUTION) of light pattern in advance and carried out (for example, referring to patent documentations 1) such as so-called calibrations (calibration).
As the step of calibration, first irradiate light pattern to pre-prepd reference field and taken by image unit.Then, obtain the brightness value of each coordinate (pixel) on the image of shooting, and calculate the phasing degree of the light pattern at each coordinate place based on this brightness value, and store this phasing degree.When carrying out the three-dimensional measurement of phase-shifting method, during calibration also in time surveying in the same manner as the phase place of light pattern is such as changed with four-stage, obtain the image of intensity distributions with correspondence with it, and obtain the phasing degree at each coordinate place
Then, when carrying out three-dimensional measurement, the phasing degree of the phasing degree of each coordinate stored after calibration with each coordinate calculated based on the brightness value of surveying is compared, calculate the bias of the coordinate with same phase angle, and obtain the height of preset coordinates position based on the principle of above-mentioned triangulation.
Such as, when the measured value (phasing degree) at preset coordinates position (X, Y) place is " 10 ° ", detect should the value of " 10 ° " be positioned at calibration after go the data that store where.Here, if existing " 10 ° " relative to the position of preset coordinates position (X, Y) apart from 3 pixels, then represent that the striped of light pattern deviate from three pixels.Then, the height (Z) of preset coordinates position (X, Y) can be obtained according to the principle of triangulation based on the bias of the striped of the irradiating angle of light pattern and light pattern.
Look-ahead technique document
Patent documentation
Patent documentation 1: Japanese Patent Laid-Open 2005-337943 publication.
Summary of the invention
The problem that invention will solve
But as mentioned above, in the past, each band electrode of liquid crystal grating was respectively by drivings such as different transistors, and the brightness value of each position being irradiated to measured object is also different according to each position, therefore needs to calibrate whole measurement range.
In addition, as shown in figure 16, such as when wanting to measure the height of the some P suitable with the end points of measurement range W1 (the some O ~ P on reference field), not only need the light pattern to being irradiated to measurement range W1 to calibrate, but also need to calibrate the light pattern being irradiated to the scope W2 (the some P ~ Q on reference field) corresponding with measuring height scope V.Namely the calibration range W3 larger than measurement range W1 is needed.In other words, measurement range W1 must be set narrower than the image pickup scope (range of exposures of lighting device 90) of camera 91.
The possibility of result causes measuring efficiency and declines.The situation that the situation and being undertaken by the phase-shifting method employing sinusoidal wave light pattern that the problems referred to above are not limited to measure the height of the solder cream be printed on printed base plate etc. is measured also is exist in the field of other three-dimensional measuring apparatus.
The present invention completes in view of the above problems, and its object is to provides the three-dimensional measuring apparatus that effectively can improve measuring accuracy.
For the means of dealing with problems
Below, subitem illustrates each means for solving the problem.In addition, action effect specific to corresponding means is also charged to according to necessity.
Means 1: a kind of three-dimensional measuring apparatus, is characterized in that, comprising:
Illumination unit, described illumination unit comprises the liquid crystal grating of the light source launching predetermined light and the light pattern light from this light source being converted to the light distribution with striated, and described illumination unit at least can irradiate this light pattern to measured object;
Image unit, described image unit can take the reflected light of the described measured object from illuminated described light pattern; And
Graphics processing unit, described graphics processing unit carries out three-dimensional measurement based on the view data of being made a video recording by described image unit;
Wherein, described liquid crystal grating comprises:
A pair transparency carrier opposite each other;
Be arranged on the liquid crystal layer between described two transparency carriers;
Be arranged on the public electrode in the one in described a pair transparency carrier; And
To be arranged in the another one in described a pair transparency carrier and to separate multiple band electrodes that predetermined space arranges in parallel to each other;
Wherein, described liquid crystal grating is configured to the transmitance by controlling to change to the voltage applied between described public electrode and described band electrode described liquid crystal layer,
Described multiple band electrode being divided into n band electrode is multiple band electrode groups of 1 group, and wherein n is the natural number of more than 2, and
The band electrode being i-th by putting in order in described each group is connected in parallel with each other, and wherein i is the natural number of 1≤i≤n,
Described liquid crystal grating also comprises n on-off element, and a described n on-off element is connected with the described n be connected in parallel a band electrode group respectively, and controls the voltage to this band electrode group applying,
Described multiple band electrode group is by parallel drive.
According to above-mentioned means 1, n band electrode is connected in parallel with each other as the band electrode that putting in order in multiple band electrode groups of 1 group is i-th, be connected with an on-off element respectively in the described n be connected in parallel a band electrode group, and controlled by this on-off element respectively.That is, the voltage that the band electrode being i-th to putting in order in multiple band electrode group applies is identical in each band electrode group.Therefore, even if when the voltage generation deviation applied to each band electrode in each band electrode group, the light distribution of the light pattern formed by multiple band electrode group is also identical respectively in each band electrode group.Thus, by only calibrating the scope corresponding with band electrode group, the result identical with when calibrating the whole region of measurement range just can be obtained.And, because calibration range is less than measurement range, therefore, it is possible to effectively utilize the whole region of the coverage of image unit, such as, whole for the image pickup scope of image unit region (the whole region of range of exposures of lighting unit) can be set as measurement range etc.As a result, effectively measuring accuracy can be improved.
Means 2: the three-dimensional measuring apparatus according to means 1, it is characterized in that, comprise grating control module, described grating control module controls the switching of described grating, be multiple to make the phase change with the light pattern of sinuous light distribution irradiated from described illumination unit
Wherein, described graphics processing unit is based on multiple view data and carry out three-dimensional measurement by phase-shifting method, and phase change is that multiple described light pattern obtains based on irradiation by described multiple view data.
By above-mentioned means 2, bias component and modulation product can be eliminated by phase-shifting method, therefore, it is possible to improve measuring accuracy further.
Means 3: the three-dimensional measuring apparatus according to means 2, is characterized in that, described band electrode group comprises 12 strip electrodes.
According to above-mentioned 3, can by making each phase shift of the phase place of light pattern 120 ° of 2 π/3) and from the method for three kinds of image data acquisition phase data with make each phase shift of the phase place of light pattern 90 ° (pi/2s) and switch from these two kinds of methods of method of four kinds of image data acquisition phase data, change fringe spacing (measurable height resolution).Consequently, versatility can be improved and improve measuring accuracy further.
Accompanying drawing explanation
Fig. 1 is the Sketch figure schematically showing base board checking device;
Fig. 2 is the block diagram of the electrical structure that base board checking device is shown;
Fig. 3 is the Sketch figure schematically showing liquid crystal grating;
(a) of Fig. 4 is the figure through luminance level at each position being shown schematically in liquid crystal grating the striated grating pattern being changed to three kinds, and (b) of Fig. 4 schematically shows the figure forming the capable light and shade state of each grating of this grating pattern;
(a) of Fig. 5 is the figure of the deviation through luminance level at each position schematically showing the striated grating pattern be formed on liquid crystal grating, and (b) of Fig. 5 is the figure of the deviation of the light distribution schematically showing the light pattern irradiated via this grating pattern;
Fig. 6 is the figure of the relation for illustration of measurement range and calibration range;
(a) of Fig. 7 schematically shows the figure through luminance level being changed to each position of the striated grating pattern of four kinds in liquid crystal grating that other embodiments relate to, and (b) of Fig. 7 is the figure schematically showing the capable light and shade state of each grating of forming this grating pattern;
Fig. 8 is the figure being shown schematically in the capable light and shade state of each grating of forming the striated grating patterns of four kinds or three kinds changes in liquid crystal grating that other embodiments relate to;
Fig. 9 is the Sketch figure of the circuit structure schematically showing the liquid crystal grating that other embodiments relate to;
Figure 10 is the figure for illustration of the height and position of printed base plate and the relation of irradiated light pattern;
Figure 11 is the figure of the calibration range related to for illustration of other embodiments etc.;
(a) of Figure 12 is the figure through luminance level at each position of the striated grating pattern schematically shown on the liquid crystal grating that is formed in the past, and (b) of Figure 12 is the figure of the light distribution schematically showing the light pattern irradiated via this grating pattern;
Figure 13 illustrates the figure for illustration of the position relationship using the lighting device of height operational method of principle of triangulation and measuring position coordinate etc.;
Figure 14 is the figure of the pattern schematically showing the striated light pattern be radiated on measured object;
(a) of Figure 15 is the figure of the deviation through luminance level at each position of the striated grating pattern schematically shown on the liquid crystal grating that is formed in the past, and (b) of Figure 15 is the figure of the deviation of the light distribution schematically showing the light pattern irradiated via this grating pattern;
Figure 16 is the figure of the relation for illustration of measurement range and calibration range.
Embodiment
Below, with reference to accompanying drawing, an embodiment is described.
Fig. 1 is the Sketch figure of the base board checking device 1 schematically showing the three-dimensional measuring apparatus had in present embodiment.As shown in the drawing, base board checking device 1 comprises: for loading the mounting table 3 of the printed base plate 2 as measured object, wherein printed base plate 2 is printed with the solder cream as measuring object; As the lighting device 4 of illumination unit, it irradiates predetermined light pattern from oblique upper to the surface of printed base plate 2; As the camera 5 of image unit, for taking the part of being irradiated by light pattern on printed base plate 2; And control device 6, for implementing various controls in base board checking device 1, image procossing, calculation process.
Mounting table 3 is provided with motor 15,16, by motor 15,16 controlled device 6 (motor control unit 23) drived control, the printed base plate 2 be positioned in mounting table 3 is slided to arbitrary direction (X-direction and Y direction).
Lighting device 4 comprises: launch the light source 4a of predetermined light and the light penetrated from this light source 4a converted to the liquid crystal grating 4b of the light pattern with striated light distribution, lighting device 4 can from oblique upper to printed base plate 2 irradiate phase place with each 1/3rd the light pattern of striated that changes of spacing.
In more detail, in lighting device 4, the light penetrated from light source 4a is directed to a pair collector lens by optical fiber, and becomes directional light in this collector lens.This directional light is directed to projecting lens via liquid crystal grating 4b.Then, from projecting lens, printed base plate 2 is irradiated to the light pattern of striated.In addition, about the detailed construction of liquid crystal grating 4b, will be described hereinafter.
Camera 5 comprises lens and picture pick-up device etc.Picture pick-up device have employed cmos sensor.Certainly, picture pick-up device is not limited to this, such as, also can adopt ccd sensor etc.The view data of being taken by camera 5, after this camera 5 inside is converted into digital signal, is imported into control device 6 (image data memory cell 24) with the form of digital signal.Then, control device 6 implements as described later based on this view data image procossing and check processing etc.From this layer meaning, control device 6 composing images processing unit.
Then, the electrical structure of control device 6 is described.As shown in Figure 2, control device 6 comprises: the camera control unit 21 controlling the shooting timing of camera 5; Control the lighting control unit 22 of lighting device 4; Control the motor control unit 23 of motor 15,16; Store the image data memory cell 24 of the view data (brightness data) captured by camera 5; Store the calibration data storage unit 25 of calibration data described later; Store the phase data storage unit 26 of the phase data calculated based on described view data; The three-dimensional measurement unit 29 of three-dimensional measurement is carried out based on described calibration data and phase data; And the identifying unit 30 of the printing state of solder cream 4 is checked based on the measurement result of this three-dimensional measurement unit 29.
Though the diagram of eliminating, base board checking device 1 comprises: the input block be made up of keyboard, touch panel; There is the display unit of the display screen such as CRT or liquid crystal; For preserving the storage unit of check result etc.; And the output unit etc. to the outgoing inspection results such as solder printing machine etc.
Here, with reference to Fig. 3, the structure of liquid crystal grating 4b is described in detail.
Liquid crystal grating 4b using as the first glass substrate 31 of a pair transparency carrier and the second glass substrate 32 separated by a certain interval and stick together, and have and enclose TN (stable twisted nematic) liquid crystal etc. betwixt and the liquid crystal layer that formed.
Whole of first glass substrate 31 is formed with public electrode 33, the second glass substrate 32 on the other side is arranged with a determining deviation band electrode 34 that many have one fixed width.Public electrode 33 and band electrode 34 are formed by nesa coatings such as ITO (Indium-tin-oxide, indium tin oxide).
In addition, conveniently, in Fig. 3, illustrate only 18 strip electrodes 34, but in the liquid crystal grating 4b of reality, be altogether arranged with the band electrode 34 of about hundreds of.
In addition, though the diagram of eliminating, be configured with the first polarization plate in the outside of the first glass substrate 31, be configured with the second polarization plate in the outside of the second glass substrate 32.First polarization plate and the second polarization plate are configured to make their polarizing axis perpendicular to one another or parallel.
In liquid crystal grating 4b, the voltage driven circuit 35 under the instruction of control device 6 (lighting control unit 22) being applied to liquid crystal layer between public electrode 33 and band electrode 34 controls, and the transmitance of this part changes thus.Such as, can by applying predetermined voltage between public electrode 33 and band electrode 34 or do not apply voltage to form transmitance high " bright portion " and low " dark portion " of transmitance.By alternately being formed in such " bright portion " and " dark portion ", the grating pattern of striated can be formed.
Then, when such as irradiating the light from light source 4a from the first polarization plate side to this liquid crystal grating 4b, the light through this first polarization plate becomes the rectilinearly polarized light of the direction polarization to its polarizing axis, and by the first glass substrate 31 and public electrode 33.
Here, between public electrode 33 and band electrode 34, be such as applied in the part of predetermined voltage, by the rectilinearly polarized light non rotating of TN liquid crystal, if therefore the polarizing axis of the second polarization plate is parallel with the polarizing axis of the first polarization plate, so this linear polarization light transmission second polarization plate, becomes in " bright portion " that transmitance is the highest.
On the other hand, such as, between public electrode 33 and band electrode 34, be not applied to the part of voltage, this rectilinearly polarized light by half-twist, and arrives to the second polarization plate through band electrode 34 and the second glass substrate 32.Here, if the polarizing axis of the second polarization plate is parallel with the polarizing axis of the first polarization plate, so this rectilinearly polarized light almost through the second polarization plate, can not become " dark portion " that transmitance is minimum.
In addition, when the polarizing axis of the first polarization plate is vertical with the polarizing axis of the second polarization plate, the relation to the voltage applied between public electrode 33 and band electrode 34 and transmitance becomes contrary.
And in the present embodiment, band electrode 34 being divided into often predetermined number is the group of 1 group, and each group by parallel drive.Figure 3 illustrates that 18 strip electrodes 34 to be divided into every 6 be the example of one group 3 groups.
In more detail, among 18 strip electrodes 34, the first band electrode 34a of each group is connected in parallel each other, and this first band electrode 34a group and same first on-off element 36a (transistor etc. of the most rear class of the first band electrode 34a that Direct driver is respectively organized) are connected, and apply voltage via this first on-off element 36a to each first band electrode 34a.
Similarly, the second band electrode 34b of each group is connected in parallel with each other, 3rd band electrode 34c is connected in parallel with each other, 4th band electrode 34d is connected in parallel with each other, 5th band electrode 34e is connected in parallel with each other, and the 6th band electrode 34f is connected in parallel with each other, and the second band electrode 34b group, 3rd band electrode 34c group, 4th band electrode 34d group, 5th band electrode 34e group, and the 6th band electrode 34f group respectively with same on-off element (second switch element 36b, 3rd on-off element 36c, 4th on-off element 36d, 5th on-off element 36e, 6th on-off element 36f) connect, and apply voltage via each on-off element 36b ~ 36f to each band electrode 34b ~ 34f.
Then, the liquid crystal driving signal generated by control device 6 (having the pulse signal of the strength level of two-value) is input to driving circuit 35, thus apply between public electrode 33 and band electrode 34 or do not apply the voltage corresponding to liquid crystal driving signal, form the grating pattern of the striated comprising light transmission rate high " bright portion " and low " dark portion " of light transmission rate thus.Thus, be irradiated to light on printed base plate 2 via liquid crystal grating 4b fuzzy etc. by what caused by diffraction, become the light pattern with sinuous light distribution.
In the present embodiment, capable by any 3 gratings forming " bright portion " among the 6 strip electrode 34a ~ 34f of each group, the grating capable ((a) and (b) with reference to Fig. 4) of " dark portion " is formed by all the other 3.That is, the sinuous light pattern that 1 group of width being formed with 6 strip electrodes 34 is one-period is formed.
Further, by making the applying order of the voltage applied to 6 strip electrode 34a ~ 34f in each group change in time, phase offset can be carried out.Here, due to the first band electrode 34a of all groups each other, second band electrode 34b each other, 3rd band electrode 34c each other, 4th band electrode 34d each other, 5th band electrode 34e each other, 6th band electrode 34f has identical pattern ((b) with reference to Fig. 4) separately from each other, therefore such as in the present embodiment, by making by 3 capable " bright portions " and " dark portion " formed of grating skew 2 row at every turn, ground, the phase place of light pattern per stage 2 π/3 can be made to divide three phases to change, to make liquid crystal grating 4b ((a) with reference to Fig. 4) on the whole continuously.So the grating mode in liquid crystal grating 4b is carried out switching the function controlled and be equivalent to grating control module.In addition, the first ~ six grating in (b) of Fig. 4 represents that grating corresponding with the first ~ six band electrode 34a ~ 34f is respectively capable.
Then, the inspection step of the printed base plate 2 undertaken by base board checking device 1 is described in detail.First the calibration of the deviation (PHASE DISTRIBUTION) for grasping light pattern is carried out.
When calibration is performed, first prepare to be different from printed base plate 2, height and position is 0 and forms the reference field of plane.Reference field has identical color with the solder cream as measuring object.That is, the reflectivity of the light pattern of this reference field is equal with the reflectivity of the light pattern of solder cream.
Then light pattern is irradiated to said reference face, and take this light pattern to obtain the view data of the brightness value comprising each coordinate by camera 5.In the present embodiment, make the phase place of light pattern each phase shift 2 π/3, obtain three kinds of view data of taking under each light pattern.
Then, control device 6 calculates the phasing degree of the light pattern at each coordinate place based on above-mentioned three kinds of view data (brightness value), it can be used as calibration data to be stored in calibration data storage unit 25.
Pass through said structure, put on the first band electrode 34a group of each group, the second band electrode 34b group, the 3rd band electrode 34c group, the 4th band electrode 34d group, the 5th band electrode 34e group and the 6th band electrode 34f group voltage identical respectively, even if when there is deviation in the voltage therefore putting on each band electrode 34a group ~ 34f group as shown in (a) as Fig. 5, as shown in (b) of Fig. 5, the waveform (light distribution) of the light pattern irradiated via each group is also identical respectively.
Thus, in the present embodiment, as shown in Figure 6, do not need to calibrate the whole region of measurement range WB1, as long as using the scope suitable with the one-period of the light pattern corresponding to an electrode group as calibration range WB2.
Then, the auditing routine that each inspection area is carried out is described in detail.This auditing routine is performed by control device 6.
Control device 6 (motor control unit 23) first carries out drived control to move printed base plate 2 to motor 15,16, and the predetermined inspection area (measurement range) on printed base plate 2 is aimed in the visual field of camera 5.Inspection area is the region that the surface of printed base plate 2 to be split in the region obtained by a unit in advance with the size of the visual field of camera 5.
Then, the liquid crystal grating 4b of control device 6 illumination apparatus 4 carries out switching and controls, and the position of the grating that this liquid crystal grating 4b is formed is set to predetermined reference position.
After the switching of liquid crystal grating 4b has set, control device 6 makes the light source 4a of lighting device 4 luminous by lighting control unit 22, start to irradiate predetermined light pattern, and carry out drived control by camera control unit 21 pairs of cameras 5, start to take the inspection area part of this light pattern illuminated.The view data of being taken by camera 5 is transmitted to image data storage apparatus 24 and is stored.
Similarly, above-mentioned a series of process is being carried out by under two kinds of light patterns of each for the phase place of light pattern phase shift 2 π/3.Thus, about predetermined inspection area, three kinds of view data of taking under each light pattern of each skew 2 π/3 phase places can be obtained.
Then, control device 6 calculates the phasing degree of the light pattern of each coordinate from above-mentioned three kinds of view data (brightness value) by phase-shifting method, and it can be used as phase data to be stored in phase data storage unit 26.
Afterwards, control device 6 (three-dimensional measurement unit 29) compares the calibration data be stored in calibration data storage unit 25 (phasing degree based on each coordinate of calibration) and the phase data (phasing degree based on each coordinate of actual measurement) be stored in phase data storage unit 26, is obtained the altitude information at each coordinate place of inspection area by the known method also illustrated in the introduction.
And, control device 6 (three-dimensional measurement unit 29) detects the print range of the solder cream higher than reference field, by carrying out to the height at each position the amount that integration calculates printed solder cream within the scope of this based on the altitude information at each coordinate place of the inspection area obtained.
Then, the data such as the position of the such as above-mentioned solder cream obtained, area, height or amount and the reference data prestored are compared judgement by control device 6 (identifying unit 30), in allowed band, whether judge the quality of the printing state of the solder cream in this inspection area according to this comparative result.
During carrying out described process, control device 6 pairs of motors 15,16 carry out drived control and move to next inspection area to make printed base plate 2, afterwards, by repeating the inspection that above-mentioned a series of process completes printed base plate 2 entirety in all inspection areas.
As mentioned above, according to the present embodiment, have employed the group that band electrode 34 is divided into every 6 one group and often group by the structure of parallel drive.Say in further detail, band electrode 34a ~ the 34f of each group is connected in parallel separately from each other, and band electrode 34a group ~ 34f group that this is connected in parallel is connected to same on-off element 36a ~ 36f respectively, and is controlled respectively by this on-off element 36a ~ 36f.That is, the voltage being applied to the band electrode 34a group ~ 34f group of each group is identical respectively.Therefore, even if when the voltage being in application to each band electrode 34a group ~ 34f group exists deviation, the light distribution via each group of irradiated light pattern is also identical respectively.Thus, using being equivalent to organize with one the scope of the one-period of corresponding light pattern as calibration range WB2, the result identical with when calibrating the whole region of measurement range WB1 can be obtained.And, because calibration range WB2 is less than measurement range WB1, effectively can utilize the whole region of the image pickup scope of camera 5, such as, whole for the image pickup scope of camera 5 region (the whole region of range of exposures of lighting device 4) can be set as measurement range WB1 etc.As a result, effectively measuring accuracy can be improved.
In addition, be not limited to the contents of above-mentioned embodiment, such as, also can implement as follows.Certainly, also can implement with other application examples, variation not illustrative below.
A () in the above-described embodiment, three-dimensional measuring apparatus is embodied as the base board checking device 1 that the height of the solder cream that printing is formed on printed base plate 2 is measured, but be not limited thereto, such as, also can be embodied as the structure that the solder projection be printed on substrate or the height that is arranged on other objects such as electronic unit on substrate are measured.
B (), in the phase-shifting method of above-mentioned embodiment, is configured to the phase place of light pattern is changed with the spacing of 1/3rd at every turn, but is not limited thereto, also can be configured to the phase place of light pattern is changed with the spacing of 1/4th at every turn.
Such as, as shown in (a), (b) of Fig. 7, also can be configured to group band electrode 34 being divided into every 4 group, and each group of parallel drive.According to described structure, can be capable by any 2 gratings forming " bright portion " in the band electrode 34 of 4 of each group, there is the grating of all the other 2 formation " dark portion " capable.Further, during phase shift, by making, by 2 capable " bright portions " and " dark portion " formed of grating skew 1 row at every turn, the phase place of light pattern can be made to divide four-stage, each phasic change pi/2.
In addition, as shown in Figure 8, group band electrode 34 being divided into 12 group can be also configured to, and each group of parallel drive.According to described structure, by to making each phase shift of the phase place of light pattern 120 ° (2 π/3) and obtaining the method for phase data from three kinds of view data and make each phase shift of the phase place of light pattern 90 ° (pi/2s) and switch from these two kinds of methods of method that four kinds of view data obtain phase data, change fringe spacing (measurable height resolution).Consequently, versatility can be improved and improve measuring accuracy further.
C () in the above-described embodiment, is configured to irradiate sinuous light pattern, and carries out three-dimensional measurement by phase-shifting method, but measuring method is not limited thereto.Such as also can be configured to not carry out phase shift but the phasing degree of trying to achieve each coordinate from the brightness value of an irradiation light pattern gained, and carry out elevation carrection based on the principle of triangulation.
In addition, irradiated light pattern is also not limited to sinuous pattern, such as, also can adopt the light pattern that triangle is wavy, the distribution of rectangle wavy isocandela is different with position.
D () in the above-described embodiment, is configured to multiple band electrodes 34 in liquid crystal grating 4b all by parallel drive, but is not limited thereto, also can be configured to the band electrode 34 with a part of drive.Certainly, drive portion can be set in multiple position.By arranging the drive portion different from parallel drive portion, the measurement operation etc. that same light source (liquid crystal grating) carries out multiple types simultaneously can be passed through.
Such as, as shown in Figure 9, also can be configured to comprise drive portion 42 that is different from parallel drive portion 41, adjacent 4 strip electrodes 34 of drive.According to described structure, 1 the thick row (cord) be made up of " bright portion " or " dark portion " can be formed.By when slightly row is irradiated to printed base plate 2 and is undertaken taking by camera 5, as shown in Figure 10, due to the height and position of printed base plate 2, the position of the range of exposures WD1 of cord is departed from the image data.Utilize this phenomenon, printed base plate 2 bias in the height direction can be revised.Such as, as shown in figure 11, when calibrating the scope WC1 about parallel drive portion 41, for the range of exposures WC2 of the cord about drive portion 42, its position is also stored.Then, when surveying, by moving camera 5 grade in the height direction with the position making the range of exposures WC2 of cord aim at described storage, thus can corrected altitude.
E () in the above-described embodiment, be configured to the phasing degree calculating the light pattern at each coordinate from view data (brightness value), and it can be used as calibration data to store, but the data prestored are not limited to this, such as, also can be configured to the bias storing the desirable phasing degree at each coordinate place and the phasing degree of actual measurement.
Label declaration
1 ... base board checking device, 2 ... printed base plate, 4 ... lighting device, 4a ... light source, 4b ... liquid crystal grating, 5 ... camera, 6 ... control device, 24 ... image data memory cell, 25 ... calibration data storage unit, 26 ... phase data storage unit, 31,32 ... glass substrate, 33 ... public electrode, 34 (34a ~ 34f) ... band electrode, 36a ~ 36f ... on-off element, WB1 ... measurement range, WB2 ... calibration range.
Claims (3)
1. a three-dimensional measuring apparatus, is characterized in that, comprising:
Illumination unit, described illumination unit comprises the liquid crystal grating of the light source launching predetermined light and the light pattern light from this light source being converted to the light distribution with striated, and described illumination unit at least can irradiate this light pattern to measured object;
Image unit, described image unit can take the reflected light of the described measured object from illuminated described light pattern; And
Graphics processing unit, described graphics processing unit carries out three-dimensional measurement based on the view data of being made a video recording by described image unit;
Wherein, described liquid crystal grating comprises:
A pair transparency carrier opposite each other;
Be arranged on the liquid crystal layer between described two transparency carriers;
Be arranged on the public electrode in the one in described a pair transparency carrier; And
To be arranged in the another one in described a pair transparency carrier and to separate multiple band electrodes that predetermined space arranges in parallel to each other;
Wherein, described liquid crystal grating is configured to the transmitance by controlling to change to the voltage applied between described public electrode and described band electrode described liquid crystal layer,
Described multiple band electrode being divided into n band electrode is multiple band electrode groups of 1 group, and wherein n is the natural number of more than 2, and
The band electrode being i-th by putting in order in described each group is connected in parallel with each other, and wherein i is the natural number of 1≤i≤n,
Described liquid crystal grating also comprises n on-off element, and a described n on-off element is connected with n the band electrode group be connected in parallel respectively, and controls the voltage to this band electrode group applying,
Described multiple band electrode group by parallel drive,
The calibration data that view data from the region corresponding with the scope of predetermined band electrode group obtains is applied in the three-dimensional measurement carried out based on the view data in region corresponding to the scope of the band electrode group with other by described graphics processing unit, and obtains altitude information.
2. three-dimensional measuring apparatus according to claim 1, is characterized in that,
Comprise grating control module, described grating control module controls the switching of described grating, to make the phase change with the light pattern of sinuous light distribution irradiated from described illumination unit be multiple,
Wherein, described graphics processing unit is based on multiple view data and carry out three-dimensional measurement by phase-shifting method, and phase change is that multiple described light pattern obtains based on irradiation by described multiple view data.
3. three-dimensional measuring apparatus according to claim 2, is characterized in that,
Described band electrode group comprises 12 band electrodes.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012-029288 | 2012-02-14 | ||
| JP2012029288A JP5643241B2 (en) | 2012-02-14 | 2012-02-14 | 3D measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103245301A CN103245301A (en) | 2013-08-14 |
| CN103245301B true CN103245301B (en) | 2016-04-27 |
Family
ID=48924984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210275511.5A Active CN103245301B (en) | 2012-02-14 | 2012-07-31 | Three-dimensional measuring apparatus |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP5643241B2 (en) |
| CN (1) | CN103245301B (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI756165B (en) * | 2014-11-25 | 2022-03-01 | 以色列商奧寶科技有限公司 | Illumination intensity control apparatus and method, and optical inspection system |
| JP6027204B1 (en) * | 2015-10-05 | 2016-11-16 | Ckd株式会社 | 3D measuring device |
| JP6566832B2 (en) * | 2015-10-16 | 2019-08-28 | Ckd株式会社 | 3D measuring device |
| JP6062523B1 (en) * | 2015-11-27 | 2017-01-18 | Ckd株式会社 | 3D measuring device |
| JP6259806B2 (en) * | 2015-12-24 | 2018-01-10 | Ckd株式会社 | 3D measuring device |
| JP2017122641A (en) * | 2016-01-07 | 2017-07-13 | Ckd株式会社 | Three-dimensional measurement device |
| JP6306230B1 (en) * | 2017-02-09 | 2018-04-04 | Ckd株式会社 | Solder printing inspection apparatus, solder printing inspection method, and substrate manufacturing method |
| JP6925195B2 (en) * | 2017-07-28 | 2021-08-25 | シチズン時計株式会社 | Light modulation element |
| US10731976B2 (en) | 2017-10-02 | 2020-08-04 | Liqxtal Technology Inc. | Optical sensing device and structured light projector |
| CN109709743B (en) * | 2019-01-09 | 2021-04-20 | 深圳市光鉴科技有限公司 | Structured light projector and 3D camera |
| JP7231433B2 (en) * | 2019-02-15 | 2023-03-01 | 株式会社キーエンス | Image processing device |
| CN112764277B (en) * | 2020-12-28 | 2022-03-15 | 电子科技大学 | Four-step phase-shift sinusoidal fringe field projection module based on liquid crystal negative |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1564930A (en) * | 2002-02-28 | 2005-01-12 | Ckd株式会社 | Three-dimensional measuring apparatus |
| CN101889190A (en) * | 2007-08-08 | 2010-11-17 | Ckd株式会社 | Three-dimensional measurement device and board inspecting machine |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0619255B2 (en) * | 1988-07-08 | 1994-03-16 | 工業技術院長 | Interferometer and interferometer for aspherical surface measurement by optical spatial light modulator using liquid crystal |
| JP3831089B2 (en) * | 1997-09-10 | 2006-10-11 | シチズン時計株式会社 | 3D shape measuring device using lattice pattern projection method |
| JP2003083772A (en) * | 2001-09-11 | 2003-03-19 | Citizen Watch Co Ltd | Size measuring apparatus using optical scale |
| JP4611782B2 (en) * | 2005-03-28 | 2011-01-12 | シチズンホールディングス株式会社 | Three-dimensional shape measuring method and measuring apparatus |
-
2012
- 2012-02-14 JP JP2012029288A patent/JP5643241B2/en active Active
- 2012-07-31 CN CN201210275511.5A patent/CN103245301B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1564930A (en) * | 2002-02-28 | 2005-01-12 | Ckd株式会社 | Three-dimensional measuring apparatus |
| CN101889190A (en) * | 2007-08-08 | 2010-11-17 | Ckd株式会社 | Three-dimensional measurement device and board inspecting machine |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5643241B2 (en) | 2014-12-17 |
| JP2013167464A (en) | 2013-08-29 |
| CN103245301A (en) | 2013-08-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103245301B (en) | Three-dimensional measuring apparatus | |
| KR101118195B1 (en) | Three-dimensional measurement device | |
| CN105390111B (en) | The detection method and detection device of sequence controller | |
| KR101152842B1 (en) | Three-dimensional measurement device and board inspecting machine | |
| CN103162641B (en) | Three-dimensional measuring apparatus | |
| KR101121691B1 (en) | Three-dimensional measurement device | |
| US8693007B2 (en) | Device for measuring three dimensional shape | |
| JP5443303B2 (en) | Appearance inspection apparatus and appearance inspection method | |
| US10215556B2 (en) | Three-dimensional measuring apparatus | |
| US9417053B2 (en) | Three-dimensional measuring device | |
| JP6522344B2 (en) | Height detection device, coating device and height detection method | |
| CN103162642B (en) | Three-dimensional measuring apparatus | |
| JP2017110991A (en) | Measurement system, measurement method, robot control method, robot, robot system, and picking device | |
| US10514253B2 (en) | Three-dimensional measurement apparatus | |
| JP5612969B2 (en) | Appearance inspection apparatus and appearance inspection method | |
| CN105355183A (en) | Liquid crystal display driving system | |
| CN101893766B (en) | Method and device for realizing phase shift by changing incident angle of light | |
| JPH0719825A (en) | Substrate inspection apparatus | |
| JP4947559B2 (en) | 3D measuring device | |
| WO2016203668A1 (en) | Three-dimensional measurement device | |
| TWI481814B (en) | Three dimensional measuring device | |
| CN107429992B (en) | Three-dimensional measuring apparatus and method for three-dimensional measurement | |
| JP6847088B2 (en) | Projection device and 3D measuring device | |
| JP2018054373A (en) | Inspection device, inspection method, inspection program, and method of manufacturing object |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |